Successively-operated tone modulator



April 3, 1928. 1,664,553

J. H. HAMMOND, JR

SUCCESSIVELY OPERATED TONE MODULATORS M Filed Aug. 12I 1925 I5 Sheets-Sheet 1 1 'l f A c n I av 60 fl Illl Illll [mentar Pff/,9, www

April 3, 1928.

J. H. HAMMOND, .1R

SUCCESSIVELY OPERATED TONE MODULATORS Filed Aug. 12, 192.5 5 Sheets-Sheet 2 1,664,553 J. H. HAMMOND, JR

SUCCESSIVELY OPERATED TONE MODULATORS Filed Aug. l2, 1925 5 Sheets-Sheet 3 v ff' A April 3, 1928.

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ign/mn Mmm Patented Apr. 3, 1928.

' UNITED STATES JOHN HAYS HAMMOND, JR., F GLOUCESTER, MASSACHUSETTS.

SUCCESSIVELY-OPERATED TONE VIVIODULATOIR- Application led August 12,A 1925. Serial No. 49,823.

This invention relates to musical inst-rw ments of thc percussive type and more' particularly to the improvement ot' theA tone control ot such instruments.

T he principal objects of the present invention are to provide an improved stringed instrument including rmeans ior )iotlucing` sound positioned Within al substantially soundprooir casing; to provide means tor producing,i and controlling; a highly damped musical note; to provide improved tone reflectors forregulating the volume ot sound emitted from the instrument While the note is sustained; to provide an improved mechanism 'tor operating the tone retlectors at dill'ercnt times with respect to each other; and to provide other features as will appear hereinafter.

The quality of the music produced by a musical instrument such as a piano can be very greatly enhanced by providing' a sound insulated casing for the instrument with controllable apertures therein tor regulatingr the .folume ot sound emitted from the instrument. Furthermore an instrument so equipped can be made to produce a variety of novel effects, and can be employed to advantage in combination with lsymphonic orchestras. I have discovered that when a plurality of closuresare arranged iu difierent positions with respect to the sounding hoard and the strings, the sound emitted through the respective apertures ditier-s in duality and timbre. and I have found that 3:3 when the apertures and the closures therefor arc arranged to be opened successively the control oft the tone dynamics is `greatly in'tproved. and the attractiveness oit the music is very greatly increased. Broadly stated. the present invention relates to an improved musical instrument for producing these novel effects.

Other objects will appear from the following description taken in connection with the accompanying drawings, in which Figure 1 is a side elevation ot a piano mechanism embodying; one form ot the invent-ion; y

Figure 2 is a bottom plan view ot the 7' n'ieehanism shown in Figure 1;

`Figure B is a side elevation partly in section oit the mechanism oi Figure 1;

Figure 4- is a transverse cross section taken l' e llt-f4 Ot Figure 3; and

ure 5 is a detailed cross section of Lt t) a portion of the tone reliectors in closed position.

Like rct'erence characters refer to like parts in the several figures of the drawings.

In the following description and claims, 60 parts Will `be identified by specific names for convenience of expression7 but they are intended to be as generic in their application to similar parts or equivalent construction as the art will permit.

In the torni of the invention shown in Figures 1 to a ot the drawings, the system is illustrated as applied to a grand piano 9 having a sounding board 10 and provided with a usual keyboard piano action 11 and a plurality ot tuned strings 1Q. The piano is also provided with the usual sostenuto and loud pedal actions which are controlled by two pedals 13 and 14 (see Fig. et) operating through a pair of vertical rods 15 and 16 respectively. The pedals 13 and 14 are mounted in a block 17 which is supported by tivo spaced columns 18. 18. `These columns are attached at their upper ends to a. block 19 which is carried ly a framework oi .the piano 9.

For controlling` the sound emission from the piano. there is provided a pedal 20, which is mounted in the .block 17 and which is operatively connected to a vertical shaft 21. rlhe upper end of the shaft 2l slides in a bearing 91 and operatively connected with one arm of a bell crank lever :9.2 mounted 'tor rotation by means of a pivot 23 upon a fixed bracket 24 secured to the block 19. Pivoted to the other arm of the bell crank lever E22, is a connecting' rod 25 to Which is secured one end ot a retractile spring,7 26, the other end et which is fastened to a bracket carried by the :trame ot the piano. The other end ot the connecting rod 25 is connected to one arm ot a bell crank Which is pivoted at 31 to a bracket 32 carried by the framework of; the piano near one end of the casing. .The other arm of the second bell crank lever 30 is operatively connected to a vertically disposed sliding plate 33 by means of a ball and socket connection comprising' a hall 3ft loosely m-ountet in a` socket on the plate 33 The ball 34 is provided with a bore extending therethrough and litted to the arm et the crank 30 so as to per mit tree movement ot the arm transversely of the plate, and to transmit motion from the arm to the plate. i

The plate 33 is slidably mounted for vertical reciprocating movement in a pair of spaced fixed brackets 4() and 41 which are positioned within the piano casine. The plate is provided with differently characterized cam slots 42 and 43 into which project two pins 44 and 45 affixed to two arms 46 and 47 respectively. The arms 46 and 47 are pivotally secured upon the brackets 4f) and 4l. The free ends of the arms 46 and 47 are pivotally connected to a pair of links 50 and 51 respectively, the other ends of which are pivoted to two slidably mounted bars 52 and 53 respectively. The upper bar V52 is slidably mounted in a. pair of spaced brackets 54, '54 secured to the casing of the piano, to permit free movement along its longitudinal axis. Similarly the lower bar 53 is slidably mounted in a pair of spaced brackets 55, 55 secured to the casing and slidably mounted therein along its longitudinal axis. The bars 52 and 53 are provided with a. plurality of differently characterized cam slots, such as 56, and there projects into each slot the end of crank 57. Each of the cranks 57 is securely fastened to al tone inodulator, which may take the form of a reflector 60 and which is mounted for rotation about its longitudinal aXis upon the framework of the piano so to control the emission of sound from within ythe casing and each crank in combination with the cam. face of the respective cam slot serves to ope-rate the respective reflector or closure independently of any other. Each reflector 60 is preferably in the form of elongated flat member having beveled lateral edges and is provided on its inner surface with a layer 8O of sound reflecting material which may be of sheet metal having a smooth surface, such as sheet aluminum. lt will be noted that the tone reflectors V6() are arranged in two groups, one group associated with the upper bar 52 and arranged edectively to control the emission of sonnet in an upward direction from the casing, and the other group being associated with, the 'lower bar 53 and arranged effectively to control emission of vsound in a downward direction from the casing. It will he noted that the sound emitted upwardly is transmitted directly from the strings and by reflection from the sounding board, while the sound emitted downwardly is transmitted through the sounding board.

The cam slots 56 in the upper bar 52 are formed so that longitudinal movement of the bar causes rotary movement of the reflectors of the upper group. Each slot is provided with an oblique or oft-set portion or cam face as at 6l for transforming longitudinal movement of the bar into rotary movement of the reflector, during a Vlimited part of the reciprocal movement of the bar. The remaining portion of the cam slot as indicated by way of example at 62 and 63 is arranged in substantially parallel alignment with the longitudinal axis ofthe bar so that the corresponding reciprocal movement of the bar is not transformed into rotary movement of the respective reflector. lt will be seen that the oblique or off-set parts ofthe respective cam slots of the upper bar are in staggered relation respectively so that longitudinal movement of the bar causes a successive movement of the several reflectors associatedrwith the upper bar. Similarly each cam slot 56 of the lower bar 53 is provided with an oblique or off-set portion as at 64 for transforming longitudinal movement of the bar into rotary movement of the :respective reflector during a limited part of the reciprocal movement of the bar. The remaining portion of the cam slot as indicated by way of example at 65 and 66 is arranged in substantially parallel alignment with the longitudinal axis of the bar so that the corresponding reciprocal movement of the bar is not'transformed into rotary movement of the respective reflector. It will be seen that the oblique or off-set part-s of the respective cam slots of the lower bar are in staggered relation so that longitudinal movement of the har causes a successive movement of the several reflectors associated with the lower bar. Y

Furthermore the oblique or off-set portions of the cam. slots of the lower bar may be in any desired relation with respect to the corresponding cam slots of the upper bar, to cause any desired relative movement of the groups of bars and thus to produce a predetermined opening of the lower group of reflectors with respect to the opening of the upper group of reflectors.

Each of the cam slots 42, 43 in the vertical' plate 33 alsocomprises an portion parallel to the line of movement of the plate (see Figure 3) as indicated at 67, and a portion at an oblique angle thereto. When the pin 45 projects into the parallel portion the arm 47 is not affected by movement of the plate. 1When the plate has been moved into position so that the pin 45 projects into the angularly disposed portion of its cam slot, however, movement of the plate longitudinally causes rotary movement of the respective arm 47. The other cam slot 42 also includes similar oblique and parallel portions, as indicated respectively at G8 and 69, but the order of arrangement of these portions may be different from that of the other cam slot, to produce a differently timed movement ofthe reflectors associated therewith relative to the other groups of reflectors. ln the arrangement shown the upper group of reflectors close first, and subsequently the lower group is closed.

The pin 44 of the upper arm 46, and the cooperating-cam face of the respective cam slot 42 form collectively a cam action for the lOl) -iti

fili

upper group of tone reflectors which serves to operate the respective vgroup of reflectors independently of the lower group. Similarly the pin 45 of the lower arm 47, and the cooperating cam iace of the respective cani slot 43 form collectively a cam action Afor the lower group of toneretlectors for operating the lower group independently.

The sequence of operation of the individual reflectors or of the groups of reflectors may be moditied as may be desired by suitably changing the cutting of the cam slots 42. el?) and 56 to produce the sequence or relation oit operation desired.

As illustrated in Figure l of the drawings, the casing of the pia-no is formed of substantially soundproot material comprising an interior layer 70 of a sound absorbent material such as a padding of telt, grass or the like, and a protect-ing covering 71 of suitably finished wood or other desired material. Similarly the reflectors 60 may be formed ofi` substantially soundproof material so that when all of the reflectors are in closed position, the sound of the instrument is effectively suppressed. `lVhen the reflectors are in open or partially opened position a desired volmne of sound is emitted and thus the reflectors are effective for controlling the volume of sound produced by the instrument in different directions. As the quality or timber of the musical sound emitted in diii'erentdirections varies, extremely delicate tone shading can thus be obtained.

In the operation of the form of the invention shown in Figures l to el, the tone reflectors 6() are normally held in the open position as shown in the drawings, by means o't' the spring 7hen it is desired to close the reflectors, the pedal 2O is depressed, thereby elevating the rod 2l which rotates the bell crank 22 in a counter clockwise direction as seen in Figure Ll, causing the rod 25 to be moved to the right oi Figure' d, thus rotating the bell crank in a counter clockwise direction and causing the plate 33 to be elevated.

As the plate 33 moves upward, the pins Ll/l and -ll slide down the slots 42 and 43. As the first part ot the slot ft2 is inclined to the axis oi the bar, the pin eil will be moved to the le't't (see Figure 3) thereby rotatingthe arm counter clockwise, which in turn moves the link and the bar 52 to the left oi Figure 3. The crank 5C ot' the closure at the extreme left hand end of Figure 3 will move down the inclined part otl the corresponding slot, thereby rotating the corresponding tone reflector in a clockwise direction which will cause it to close. At this time the end of the crank ot' the adjacent retlector will be atthe top of the inclined part of the corresponding slot and continued movement of the bar 52 to the leftwill cause this crank to slide down the inclined slot, thereby quicklyclosing the corresponding tone reflector. As the bar 52 continues to move to the leit the next crank will move down the corresponding inclined slot and close its tone rel'lcctor. This action will continue as the bar 52 moves to the lett, thus cach ot the upper tone reflectors 60 will be closed successively until the last one at the right has been closed. At this time the pin -l-lwill have .lett the end of the inclined part ot' the slot l2 and as the plate 33 continues to move upward, this pin will slide down the vertical portion ot the slot Al2 and will therefore leave the arm 46 in its extreme left position without further rotation thereof.

During the first halt of thc motion of the plate S33, the pin will move down the vertical part ot' the slot 48 after which it will move down the inclined part, thereby causing the arm l-T to be rotated lett in a clockwise direction, thereby moving the link 5l and the bar 53 to the left which will cause the .lower tone reflectors to be closed successively, starting with the furthest to the lett in a manner similar to that above described in connection with the upper tone reflectors. ll'hen the reflectors are in the fully closed position, a minimum of musical sound is emitted from the piano.

their it desired again to open the reflectors, the pressure on the pedal 2O is released and the spring 26 restores the connect-ing rod to the lett, thereby rotating the bell crank 30 and causing the plate 33 to be moved downwardly. This will reverse the motion ot the arms 4.6 and 47 and will iii-st cause the lower tone reflectors to be opened successively, starting with the one farthest to the right and after this set is entirely opened, the upper tone reflectors 6U will be opened successively starting with the one farthest to the right and continuing until they are all Yt'ul ly opened. Then the re lectors arc fully opened, a maximum of musical sound may be produced by the instrument. f f

Thus, by opening or closing the reflectors to desired degrees, any desired intensity of sound may be produced, with a full utilization ol' all the harmonics or partials ot' the notes, so that the tone color and timbre of the music is greatly enhanced even when musical sounds of low intensity are being produced. Furthermore the improved construction herein illustrated enables the player to control the tone dynamics very closely and to impart delicate and tine shadings to the music.

ily suitably controlling the pedal 2l the musician may modify the sound and cause delicate variations ot' sound intensity transmitted 'from any desired part ot' the instrument, and thus to impart agreeable variationsin quality to the music. By carefully adjusting and controlling the pedal, the qualities of directly transmitted sound, or of reflected sound, may be imparted in desired proportions.

rlhe invention upon which this applicaw tion is based is broader than the specific embodiment shown and described for the purpose of illustrating at least one of the ways in which it may be employed. rlhe scope of the invention is therefore to be understood as not being limited by the present specific description. l intend no limita ions other than those imposed by the claims.

That- I claim is:

l. A n'iodulating system for a pianoforte, comprising a tone modulating pedal, a plurality of tone reflectors for variably controlling the volume of sound emitted from the instrument in different directions respectively, and means including a plurality of individually differently characterized operating cams interconnectingl said pedal and said reflectors for operating the reflectors successively.

Q. A modulating system for a pianoforte, comprising` a tone modulating control device, a plurality of tone rcectors for variably controlling the volume of sound emitted from the instrument in different directions respectively, and means including a plurality oitl individually differently characterized operating cams interconnecting` said device and said reflectors for operating the reflectors successively.

3. A modulating system for a pianoforte, comprising a plurality of tone reflectors for variably controlling the volume of sound emitted from the instrument in different directions respectively, and means for operating the reflectors successively including a plurality of individually differently characterized operating cams.

4l. A modulating system for a pianoforte comprising a plurality of tone reflectors arranged in groups, means for operating each of the tone reflectors independently, means including a plurality of individually differently characterized operating cams for operating each group of reflectors independently of the remaining groups, and a single device for actuating all of said. means.

5. A musical instrument having a vibratory sound producing element, a substantially soundproof casing having controllable apertures for controlling the emission of sound from said element in different directions, a plurality of tone reflectors for variably closing saidapertures and arranged in groups. means including a plurality of individually differently characterized operating cams for operating each group of reflectors independently of the remaining groups, and a single device for actuating all of said means.

6. In a musical instrument of the percusasmusulman Lacasse sive type, a plurality of strings tuned to notes of the musical scale, a sounding board arranged substantially parallel yto the general plane of the strings, a plurality of hammers arranged to strike the strings tuned to the notes of the musical scale respectively, means for controlling the emission from the instrument of the sound reflected from the sounding board, means for controlling the emission from the inst-rib ment of the sound transmitted through the sounding board, and a single deviceV for controlling said means successively.

7. A modulating system for a pianoforte, comprising a plurality of tone reflectors arranged in groups, a cam action for each of the tone reflectors for operating the respective reflector independently of the remaining reflectors of the group, a cam action for cach group of reflectors for operating the respective group of reflectors iiulependently of the remaining groups of reflectors, and a single device for actuating all of said camV actions to control said reflectors.

8. ln a musical instrument, the combination with a sound control device, a pedal, and means including a cam action operatively interconnecting the pedal and .said device. f

9. A.. modulating system for a pianoforte, comprising a plurality of resonating chainbers, a plurality of sound wave reflectors for variably controlling the volume of sound emitted from different restmating chambers independently, a tone modulating pedal, and means including a. pin and slot connection operatively interconnecting said pedal with said sound Wave reflectors for variably positioning the same.

l0. A modulating system for a pianoforte, comprising a plurality of resonating chambers, a plurality of sound wave reflectors for each of said chambers for variably controlling the volume of sound emitted from the respectivo chamber independently of the other chambers, a tone modulating pedal, and means including a pin and slot connection operatively,interconnecting said pedal with said sound Wave reflectors for variably positioning the same.

l1. A modulating system for a pianoforte, comprising a plurality of resonating chambers, a pluralityof groups of sound Wave reflectors for variably controlling the volume of sound emitted from the different resonating chambers independently, a single tone modulating pedal, a bar for each of said groups having cam faces cut therein, operating elements engaging said cam faces respectively, each of said elements being connected to one of said reflectors for actuating the same, and means operatively interconnecting said pedal with said bars.

12. In amusical instrument of the percussive type, a plurality of strings tuned to notes of the musical scale, a sounding board arranged substantially parallel to the general plane of the strings, a plurality of hammers arranged to strike the strings tuned to the notes of the musical scale respectively, a plurality of sound Wave relecting devices for controlling the emission from the instrument of the sound reliected from the sounding hoard, a plurality of sound Wave 10 reflecting devices for controlling the emission from the instrument of the sound transmitted through the sounding board, a tone modulating pedal, and positive direct connected means operatively connecting said pedal and said wave reflecting devices for controlling said devices selectively.

Signed at Gloucester, in the county of Essex and State of Massachusetts this 11th day of August A. D. 1925."

JOHN HAYS HAMMOND, JR. 

